Fuse.



W. G. BANKS.

FUSE.

APPLICATION FILED SEPT. 5,'191-a.

1,097,964. Patented May 26, 1914.

INVENTOI? WITNESSES V A TTORNEYS UNITED STATES PATENT OFFICE.

WILLIAM C. BANKS, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO

NORTHWESTERN CONSTRUCTION COMPANY, OF NEW YORK, N. Y.,

01 NEW YORK.

Specification of Letters Patent. Application filed September 5, 1918.Serial No. 788,201.

A CORPORATION FUSE.

Patented May26, 19 14.

To all 'who'm- 1' t may concern Be it known that I, WILLIAM C. BANKS acitizen of the United States, residing in t e borough of Bronx, city andState of New York, have invented certain new and useful Improvements inFuses, of which the following is a specification.

This invention relates to inolosed electric fuses for insertion in anelectric circuit as a protective means against loss due to the flow ofan excessive current in the circuit.

The invention is directed to the provision of a novel filling for suchan inclosed fuse surrounding the fusible element and the tergreatlyreduced.

minals to which it is connected whereby danger incident to blowing ofthe fuse is One feature of the invention resides in the provision ofafilling material for an inclosed fuse consisting of a non-conducting,noncombustible material in the form of a multiplicity of threads orfilaments, these threads being arranged irregularly in' any relationwhich they happen to occupy in the mass of material so that amultiplicity of minute air spaces are provided throughout the body offilamentary material. As a result of the employment of material of thischaracter, minute air spaces are provided throughout the material intowhich the gases generated when the fuse is disrupted may expand andwhich therefore serve to relieve high pressure conditions within theinclosure of the fuse. The material which I have found most suitable forthis purpose is a material known as glass wool, this being in the formof a multiplicity of threads of glass intertwined irregularly. Thismaterial is a good non conductor, is non-combustible and melts only atvery high temperature.

Another feature of the invention resides in the provision of a powderednon-conducting, non-combustible material around the central portionofthe fusible element which is reduced in cross-section so as to causerupture at that point and a thread-like-material around the ends of thefusible strip and'particularly around the terminals. within'theinclosure of the fuse to which the' fusible strip is connected. v

In accordance with the invention, an inclosed fuse of the usual or anysuitableconstruction is provided with a filling of a pow-- derednon-conducting material-'of -the char acter now commonly used around thecentral portion of the fusible strip, but at both ends of the inclosuredifferent material is used, this latter being in the formof-amultiphcity ofthreads so that minute air spaces are rovidedthroughout the mass of three s. Preferably, a silicate in powdered form1s employed in the central portion of the inclosure and glass wool isemployed on either side of this around the terminals to which thefusible strip is connected. With this form of filling, the powdered,material is effective in preventing the holding ofan.

are when the fuse is blown and the air spaces throughout the filamentarymaterial at the ends of the fuse assist in relieving high pressureconditions which may occur as a result of the generation of gas when thefuse is blown.

An embodiment of the invention is illus-' trated in the accompanyindrawing which shows an inclosed fuse o' a construction.

rupted. At each end of the fuse, gripping 1 members 6 semi-circular inform and tapered on their curv'edfaces are provided, one lying oneither'side of the terminal 3. The tapered surfaces of these grippingmembers 6 I are adapted to engage the end of the tube 1.

A cap 7 is provided adapted to have threaded engagement with the end'oftube 1 and to engage the gripping members 6 so as to force them into theend of tube 1 as a result of which-they will-be forced toward each otherand grip the terminal 3 between them. This construction permits ofreadily removing'the fusible strip 2 or the parts thereof after thestrip has been broken and insertion of a new strip.

Within the tube l'is a filling 8 of a noncombustible, non conductingmaterial in the form of. a multiplicity of threads irregularly disposedso that a multiplicity of minute air spaces are provided between thethreads. Preferably I employ for this purpose a material known as glasswool. This thread-like material does not fill the entire interior of thetube 1; instead, a powdered non-combustible, non-conducting material ofthe character heretofore commonly employed in inclosed fuses is emplo edin the central portion of the tube 1, that 1s, entirely around thatportion of the fusible strip 2 where disruption is caused to take placeby the diminution of the cross-sectional area of the strip. Thispowdered material is shown at 9. The thread-like material is employed atthe ends of the tube 1 inclosing the ends of the terminals 3 whichextend within the tube 1 and the connections between the terminals andthe ends of the fusible strip.

I have found in practice that with a material of the character hereinset forth, the danger incident to blowing of the fuse on the passage ofan abnormally high current is greatly reduced.

Having now described my invention, what bers at the ends thereof, afusible strip within the inclosureconnected to said members,*

and a filling of glass wool within the incloi..

sure, substantially as set forth.

2. An inclosed fuse comprising an inclosure of insulating material,metallic members at the ends thereof, terminals connected to saidmembers and projecting within the inclosure, a fusible strip within theinclosure connected to the terminals, and a filling in said inclosureconsisting of a powdered, noncombustible, non-conducting substance aboutsaid strip and glass wool about said terminals, substantially as setforth.

This specification si ed and witnessed this 2nd day of Septem er, 1913.

WILLIAM C. BANKS.

Witnesses:

CHARLES W. Scorr, FRED DASBAU.

